Connecticut Redistricting Analysis

TL;DR

This paper examines Connecticut's 2021 redistricting process, analyzing how district boundaries impact incumbents and assessing whether protections are statistically significant, using ensemble methods and district data.

Contribution

It provides a detailed analysis of incumbent protection in Connecticut's new districts and introduces an ensemble approach to evaluate the statistical significance of these protections.

Findings

Incumbent protection in new districts is statistically significant.

Ensemble analysis reveals districts are not randomly drawn.

Changes in district competitiveness are documented.

Abstract

Connecticut passed their new state House of Representatives district plan on November 18, 2021 and passed their new state Senate district plan on November 23, 2021. Each passed unanimously in their 9-person bipartisan Reapportionment Commission; however, the process has been criticized for legislators controlling the process and for the negotiations that serve to protect incumbents. This paper investigates the extent of incumbent protection in the new Assembly maps while also providing summary data on the new districts. The impact of new districts on incumbents is analyzed through the location of district borders, an ensemble analysis (using MCMC methods) to determine if the protection of incumbents constitutes a statistical outlier, and by investigating changes to competitive districts.